ICU-acquired muscle atrophy occurs commonly and worsens outcomes in adults. The incidence and severity of muscle atrophy in critically ill children are poorly characterized.
To determine incidence, ...severity and risk factors for muscle atrophy in critically ill children.
A single-center, prospective cohort study of 34 children receiving invasive mechanical ventilation for ≥48 hours. Patients 1 week- 18 years old with respiratory failure and without preexisting neuromuscular disease or skeletal trauma were recruited from a tertiary Pediatric Intensive Care Unit (PICU) between June 2015 and May 2016. We used serial bedside ultrasound to assess thickness of the diaphragm, biceps brachii/brachialis, quadriceps femoris and tibialis anterior. Serial electrical impedance myography (EIM) was assessed in children >1 year old. Medical records were abstracted from an electronic database.
Respiratory failure requiring endotracheal intubation for ≥48 hours.
The primary outcome was percent change in muscle thickness. Secondary outcomes were changes in EIM-derived fat percentage and "quality".
Of 34 enrolled patients, 30 completed ≥2 ultrasound assessments with a median interval of 6 (IQR 6-7) days. Mean age was 5.42 years, with 12 infants <1 year (40%) and 18 children >1 year old (60%). In the entire cohort, diaphragm thickness decreased 11.1% (95%CI, -19.7% to -2.52%) between the first two assessments or 2.2%/day. Quadriceps thickness decreased 8.62% (95%CI, -15.7% to -1.54%) or 1.5%/day. Biceps (-1.71%; 95%CI, -8.15% to 4.73%) and tibialis (0.52%; 95%CI, -5.81% to 3.40%) thicknesses did not change. Among the entire cohort, 47% (14/30) experienced diaphragm atrophy (defined a priori as ≥10% decrease in thickness). Eighty three percent of patients (25/30) experienced atrophy in ≥1 muscle group, and 47% (14/30)-in ≥2 muscle groups. On multivariate linear regression, increasing age and traumatic brain injury (TBI) were associated with greater muscle loss. EIM revealed increased fat percentage and decreased muscle "quality".
In children receiving invasive mechanical ventilation, diaphragm and other skeletal muscle atrophy is common and rapid. Increasing age and TBI may increase severity of limb muscle atrophy. Prospective studies are required to link muscle atrophy to functional outcomes in critically ill children.
Wound healing is an appropriate response to inflammation and tissue injury in the gastrointestinal tract. If wound healing responses are excessive, perpetuated, or prolonged, they lead to fibrosis, ...distortion of tissue architecture, and loss of function. This introductory editorial and the minireviews or reviews in this themes series highlight the diversity in severity and location of fibrosis in response to gastrointestinal inflammation. The multiplicity of cellular and molecular mediators and new players, including stem cells or extracellular matrix-producing cells derived from nonmesenchymal cell types, is reviewed. Comparisons of inflammation-induced fibrosis across organ systems and the need for integrated and systems-based molecular approaches, new imaging modalities, well-characterized animal models, cell culture models, and improved diagnostic or predictive markers are reviewed. To date, intestinal fibrosis has received much less attention than inflammation in terms of defining mechanisms and underlying causes. This themes series aims to illustrate the importance of research in this area in gastrointestinal health and disease.
This analysis examined the role of a National Institutes of Health (NIH) individual Mentored Career Development Award (K01, K08, K23) on launching and sustaining independent research careers for ...early-career scientists, and investigated the effects of these awards during and after the doubling of the NIH budget.
The authors used grants data from the NIH covering the period 1990 through 2016, and compared success in receipt of R01 equivalent awards (R01 Eq.) and Research Project Grants (RPGs) for K awardees and K applicants who did not receive funding. The analysis combined regression discontinuity design with coarsened exact matching, and regression.
Overall, receipt of K award was associated with a 24.1% increase in likelihood of first independent NIH award (P < .01), and a larger number of R01 Eq. and RPG awards. After accounting for first major independent awards, K awards were uncorrelated with receiving second major independent research awards. Comparing different funding periods, K01 awards were predictive of subsequent R01 Eq. and RPG awards after but not during the NIH doubling, K08 awards were predictive only during the NIH doubling, and K23 awards were predictive during both periods.
Receipt of Mentored Career Development Awards was linked to increased likelihood that early-career scientists successfully transitioned to an independent research career. These findings indicate that extending funding to additional K award applicants with meritorious scores could significantly strengthen the pipeline of biomedical researchers. In addition, enhancing K awards may be relevant to sustaining research careers for clinician scientists.
To evaluate the effect of Rho kinase (ROCK)-inhibitor eye drops on a corneal endothelial dysfunction primate model and human clinical case series of corneal endothelial dysfunction.
As a ...corneal-endothelial partially injured model, the corneal endothelium of seven cynomolgus monkeys was damaged by transcorneal freezing; 10 mm of rock inhibitor Y-27632 was then applied topically 6 times daily. The phenotype of the reconstructed corneal endothelium was evaluated by immunohistochemical analysis and noncontact specular microscopy. For clinical study, the effect of Y-27632 eye drops after transcorneal freezing was evaluated in eight corneal endothelial dysfunction patients: four central corneal edema patients and four diffuse corneal edema patients.
Slit-lamp microscopy revealed that both Y-27632-treated and -nontreated corneas became hazy after transcorneal freezing, and then recovered their transparency within 4 weeks. ROCK inhibitor Y-27632 promoted recovery of corneal endothelial cell density and wound healing in terms of both morphology and function. The percentage of ZO-1 and Na(+)/K(+)-ATPase positive cells in the regenerated area in the Y-27632 group was significantly higher than in the controls. Noncontact specular microscopy revealed that corneal endothelial cell density was significantly higher in the Y-27632 group compared with the controls at 4 weeks; cell density reached approximately 3000 cells/mm(2), as opposed to 1500 cells/mm(2) in the control group. In addition to the animal study findings, the clinical study findings showed that Y-27632 eye drops effectively improved corneal edema of corneal endothelial dysfunction patients with central edema.
These findings show that rock inhibitor Y-27632 eye drops promote corneal endothelial wound healing in a primate animal model and suggest the possibility of Y-27632 as a novel therapeutic modality for certain forms of corneal endothelial dysfunction. (http://www.umin.ac.jp/ctr/ number, UMIN000003625.).
The paradigm‐changing opportunities of biologging sensors for ecological research, especially movement ecology, are vast, but the crucial questions of how best to match the most appropriate sensors ...and sensor combinations to specific biological questions and how to analyse complex biologging data, are mostly ignored.
Here, we fill this gap by reviewing how to optimize the use of biologging techniques to answer questions in movement ecology and synthesize this into an Integrated Biologging Framework (IBF).
We highlight that multisensor approaches are a new frontier in biologging, while identifying current limitations and avenues for future development in sensor technology.
We focus on the importance of efficient data exploration, and more advanced multidimensional visualization methods, combined with appropriate archiving and sharing approaches, to tackle the big data issues presented by biologging. We also discuss the challenges and opportunities in matching the peculiarities of specific sensor data to the statistical models used, highlighting at the same time the large advances which will be required in the latter to properly analyse biologging data.
Taking advantage of the biologging revolution will require a large improvement in the theoretical and mathematical foundations of movement ecology, to include the rich set of high‐frequency multivariate data, which greatly expand the fundamentally limited and coarse data that could be collected using location‐only technology such as GPS. Equally important will be the establishment of multidisciplinary collaborations to catalyse the opportunities offered by current and future biologging technology. If this is achieved, clear potential exists for developing a vastly improved mechanistic understanding of animal movements and their roles in ecological processes and for building realistic predictive models.
This paper reviews how to optimize the use of biologging techniques to answer the big questions in movement ecology. The authors identify four critical areas—questions, sensors, data and analysis—and synthesize this into an Integrated Biologging Framework (IBF), highlighting the importance of multidisciplinary collaborations and ethical issues and identify key future developments.
Corneal endothelial dysfunctions occurring in patients with Fuchs' endothelial corneal dystrophy, pseudoexfoliation syndrome, corneal endotheliitis, and surgically induced corneal endothelial damage ...cause blindness due to the loss of endothelial function that maintains corneal transparency. Transplantation of cultivated corneal endothelial cells (CECs) has been researched to repair endothelial dysfunction in animal models, though the in vitro expansion of human CECs (HCECs) is a pivotal practical issue. In this study we established an optimum condition for the cultivation of HCECs. When exposed to culture conditions, both primate and human CECs showed two distinct phenotypes: contact-inhibited polygonal monolayer and fibroblastic phenotypes. The use of SB431542, a selective inhibitor of the transforming growth factor-beta (TGF-β) receptor, counteracted the fibroblastic phenotypes to the normal contact-inhibited monolayer, and these polygonal cells maintained endothelial physiological functions. Expression of ZO-1 and Na(+)/K(+)-ATPase maintained their subcellular localization at the plasma membrane. Furthermore, expression of type I collagen and fibronectin was greatly reduced. This present study may prove to be the substantial protocol to provide the efficient in vitro expansion of HCECs with an inhibitor to the TGF-β receptor, and may ultimately provide clinicians with a new therapeutic modality in regenerative medicine for the treatment of corneal endothelial dysfunctions.
ABSTRACT
Here, we use recent U.S. National Institutes of Health (NIH) data to document trends in the NIH‐funded workforce over time. Consistent with previous studies that were initiated by NIH, we ...find that the number of scientists funded on competing R01‐equivalent (R01 Eq.) and research project grants (RPGs) increased 2–5% per year between 2009 and 2016. Primary beneficiaries of this growth were experienced investigators (Exps), whereas the share of funding awarded to early‐stage investigators (ESIs) and new investigators (NIs) declined. The decline occurred even after NIH instituted the New and Early‐Stage Investigator policy in 2009. When we evaluate the investigator pool, we find that women and racial and ethnic minorities represent a higher percentage of NIs and ESIs relative to Exps. Thus, trends of diminishing support for NIs and ESIs may negatively impact the diversity of the current and future biomedical research workforce. We find some recent gains among women and Hispanics as part of the applicant and awardee pool for both R01 Eq. and RPGs, but significant, large gaps persist among nationally underrepresented racial minorities. Our findings suggest a need to prioritize investments and support of ESIs and NIs, groups in which women and racial and ethnic minorities represent a larger proportion of the applicant pool, to enhance diversity in the NIH‐funded workforce.—Nikaj, S., Roychowdhury, D., Lund, P. K., Matthews, M., Pearson, K. Examining trends in the diversity of the U.S. National Institutes of Health participating and funded workforce. FASEB J. 32, 6410–6422 (2018). www.fasebj.org
Healthy corneal endothelium is essential for maintaining corneal clarity, as the damage of corneal endothelial cells and loss of cell count causes severe visual impairment. Corneal transplantation is ...currently the only therapy for severe corneal disorders. The greatly limited proliferative ability of human corneal endothelial cells (HCECs), even in vitro, has challenged researchers to establish efficient techniques for the cultivating HCECs, a pivotal issue for clinical applications. The aim of this study was to evaluate conditioned medium (CM) obtained from human bone marrow-derived mesenchymal stem cells (MSCs) (MSC-CM) for use as a consistent expansion protocol of HCECs. When HCECs were maintained in the presence of MSC-CM, cell morphology assumed a hexagonal shape similar to corneal endothelial cells in vivo, as opposed to the irregular cell shape observed in control cultures in the absence of MSC-CM. They also maintained the functional protein phenotypes; ZO-1 and Na(+)/K(+)-ATPase were localized at the intercellular adherent junctions and pump proteins of corneal endothelium were accordingly expressed. In comparison to the proliferative potential observed in the control cultures, HCECs maintained in MSC-CM were found to have more than twice as many Ki67-positive cells and a greatly increased incorporation of BrdU into DNA. MSC-CM further facilitated the cell migration of HCECs. Lastly, the mechanism of cell proliferation mediated by MSC-CM was investigated, and phosphorylation of Akt and ERK1/2 was observed in HCECs after exposure to MSC-CM. The inhibitor to PI 3-kinase maintained the level of p27(Kip1) for up to 24 hours and greatly blocked the expression of cyclin D1 and D3 during the early G1 phase, leading to the reduction of cell density. These findings indicate that MSC-CM not only stimulates the proliferation of HCECs by regulating the G1 proteins of the cell cycle but also maintains the characteristic differentiated phenotypes necessary for the endothelial functions.
In microorganisms, and more particularly in yeasts, a standard phenotyping approach consists in the analysis of fitness by growth rate determination in different conditions. One growth assay that ...combines high throughput with high resolution involves the generation of growth curves from 96-well plate microcultivations in thermostated and shaking plate readers. To push the throughput of this method to the next level, we have adapted it in this study to the use of 384-well plates. The values of the extracted growth parameters (lag time, doubling time and yield of biomass) correlated well between experiments carried out in 384-well plates as compared to 96-well plates or batch cultures, validating the higher-throughput approach for phenotypic screens. The method is not restricted to the use of the budding yeast Saccharomyces cerevisiae, as shown by consistent results for other species selected from the Hemiascomycete class. Furthermore, we used the 384-well plate microcultivations to develop and validate a higher-throughput assay for yeast Chronological Life Span (CLS), a parameter that is still commonly determined by a cumbersome method based on counting "Colony Forming Units". To accelerate analysis of the large datasets generated by the described growth and aging assays, we developed the freely available software tools GATHODE and CATHODE. These tools allow for semi-automatic determination of growth parameters and CLS behavior from typical plate reader output files. The described protocols and programs will increase the time- and cost-efficiency of a number of yeast-based systems genetics experiments as well as various types of screens.
Gut microbiota play an important role in regulating the development of the host immune system, metabolic rate, and at times, disease pathogenesis. The factors and mechanisms that mediate interactions ...between microbiota and the intestinal epithelium are not fully understood. We provide novel evidence that microbiota may control intestinal epithelial stem cell (IESC) proliferation in part through microRNAs (miRNAs). We demonstrate that miRNA profiles differ dramatically across functionally distinct cell types of the mouse jejunal intestinal epithelium and that miRNAs respond to microbiota in a highly cell type-specific manner. Importantly, we also show that miRNAs in IESCs are more prominently regulated by microbiota compared with miRNAs in any other intestinal epithelial cell subtype. We identify miR-375 as one miRNA that is significantly suppressed by the presence of microbiota in IESCs. Using a novel method to knockdown gene and miRNA expression ex vivo enteroids, we demonstrate that we can knock down gene expression in Lgr5+ IESCs. Furthermore, when we knock down miR-375 in IESCs, we observe significantly increased proliferative capacity. Understanding the mechanisms by which microbiota regulate miRNA expression in IESCs and other intestinal epithelial cell subtypes will elucidate a critical molecular network that controls intestinal homeostasis and, given the heightened interest in miRNA-based therapies, may offer novel therapeutic strategies in the treatment of gastrointestinal diseases associated with altered IESC function.
PDF
